Organic Letters 2009-12-17

Highly catalytic asymmetric addition of deactivated alkyl grignard reagents to aldehydes.

Chao-Shan Da, Jun-Rui Wang, Xiao-Gang Yin, Xin-Yuan Fan, Yi Liu, Sheng-Li Yu

Index: Org. Lett. 11 , 5578-5581, (2009)

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Abstract

Generally used and highly reactive RMgBr reagents were effectively deactivated by bis[2-(N,N-dimethylamino)ethyl] ether and then were employed in the highly enantioselective addition of Grignard reagents to aldehydes. The reaction was catalyzed by the complex of commercially available (S)-BINOL and Ti(O(i-)Pr)(4) under mild conditions. Compared with the other observed Grignard reagents, alkyl Grignard reagents showed higher enantioselectivity and they achieved >99% ee.